天山北缘晚新生代快速变形时间的确定及其成藏意义

Timing of Cenozoic intense deformation at the north margin of Tianshan and its implications for petroleum accumulation

生长地层分析及区域研究成果表明天山北缘冲断带晚新生代快速变形主要形成于10～7Ma以来。10Ma以来准南前陆冲断带持续扩展,形成现今地表可见的三排褶皱冲断带,其构造形成时间明显晚于天山南缘,显示印-藏碰撞引起的区域构造变形由南向北传播的特征。10Ma以来的变形强度显示天山北缘乌鲁木齐以西—齐古背斜地区的构造变形相对较弱,向两侧剥蚀作用、构造变形有所增强。晚新生代快速变形与晚期成藏匹配良好,决定冲断带前缘是油气成藏的有利部位,而山前构造带的剥蚀、隆升强烈,构造变形较弱的构造(带)应是早期成藏得以保存的有利部位。

Regional studies indicate that intense Cenozoic tectonism along the north margin of the Tianshan began between 10 Ma and 7 Ma BP. This tectonism was associated with intense deformation, leading to the formation of three thrust belts on the northern margin of the Tianshan. The timing of this intense deformation is much younger than that on the southern Tianshan, suggesting that tectonic deformation propagated from south to north, due to the India-Asia collision. The Late Cenozoic deformation resulted in the ...